package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;

    @Resource
    private StringRedisTemplate stringRedisTemplate;
//    @Autowired
//    private FollowServiceImpl followServiceImpl;

    @Resource
    private IFollowService  followServiceImpl;

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();// 获取当前页数据
        // 查询用户
       records.forEach(blog -> {
            querylogUser(blog);
            isBlogLike(blog);
       });
        System.out.println("111");
        return Result.ok(records);
    }

    /*
    * 查看博客详情
    * */
    @Override
    public Result queryBlogById(Long id) {
        //查询blog
         Blog blog = getById(id);
        //Blog blog = lambdaQuery().eq(Blog::getId, id).one();
        if(blog == null){
             return Result.fail("笔记不存在");
         }
          querylogUser(blog);
          isBlogLike(blog);
          return Result.ok(blog);
    }

    private void isBlogLike(Blog blog) {
        UserDTO user = UserHolder.getUser();
         if(user == null){
            return;
        }
         Long userId = user.getId();
        String key = "blog:liked:" + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);
    }

    @Override
    public Result likeBlog(Long id) {
        //判断是否已点赞
         Long userId = UserHolder.getUser().getId();
          String key = "blog:liked:" + id;
        //如果已点赞，就不需要再次点赞
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score == null){
             //未点赞，可以点赞
            //数据库点赞数+1
            boolean update = update().setSql("liked = liked + 1").eq("id", id).update();
            if(update){
                //保存到redis
                stringRedisTemplate.opsForZSet().add(key, userId.toString(), System.currentTimeMillis());
            }
        }else{
             //已点赞，取消点赞
            boolean update = update().setSql("liked = liked - 1").eq("id", id).update();
             if(update){
                 stringRedisTemplate.opsForZSet().remove(key, userId.toString());
             }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String  key = "blog:liked:" + id;
        // 获取top5
         Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
          if(top5 == null || top5.isEmpty()){
             return Result.ok();
         }
          List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());// 转换成Long
        String idStr = StrUtil.join(",", ids);// 将id拼接成字符串
        List<UserDTO> users = userService.query()
                .in("id",ids).last("ORDER BY FIELD(id," + idStr +")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(users);
    }

    @Override
    public Result saveBlog(Blog blog) {
        // 获取登录用户
        UserDTO user = UserHolder.getUser();
        if(user == null){
            return Result.fail("用户未登录");
        }
        blog.setUserId(user.getId());
        // 保存探店博文
 //       blog.setShopId(1L);
        save(blog);
//        boolean isSuccess = save(blog);
//         if(!isSuccess){
//            return Result.fail("新增笔记失败");
//        }
        List<Follow> follows = followServiceImpl.query().eq("follow_user_id", user.getId()).list();
          for (Follow follow : follows) {
              Long userId = follow.getUserId();
              stringRedisTemplate.opsForZSet()
                      .add("feed: "+userId,blog.getId().toString(),System.currentTimeMillis());//推送笔记到所有粉丝
          }
        // 返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        UserDTO user = UserHolder.getUser();
         String key = "feed:" + user.getId();
          Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                 .reverseRangeByScoreWithScores(key,0, max, offset, 2);//
          if(typedTuples == null || typedTuples.isEmpty()){
              return Result.ok();
          }
        List<Long> ids = new ArrayList<>(typedTuples.size());//要指定大小，不然后面要扩容
        long minTime = 0;
        int os = 1;
        for( ZSetOperations.TypedTuple<String> typedTuple : typedTuples) {
            String blogId = typedTuple.getValue();// 获取笔记id
            ids.add(Long.valueOf(blogId));
            // 获取时间戳
            long time = typedTuple.getScore().longValue();
            if (time == minTime) {
                os++;
            } else {
                minTime = time;
                os = 1;
            }
        }
        // 5.根据id查询blog
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();

         blogs.forEach(blog ->{
            querylogUser(blog);
            isBlogLike(blog);
        });
        // 6.封装并返回
        ScrollResult r = new ScrollResult();
         r.setList(blogs);
         r.setOffset(os);
         r.setMinTime(minTime);


        return Result.ok(r);
    }

   /*
* 查询用户
* */
    private void querylogUser( Blog blog){
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}
